A general wireless communication system is defined by operations performed between an eNodeB (eNB) and a user equipment (UE). A radio link from the eNB to the UE is called downlink and a radio link from the UE to the eNB is called uplink. In an advanced wireless communication system, deployment of a relay node (RN) may be considered in order to meet a demand for improved coverage and high data rates. The RN can forward a signal received from an eNB to a UE in the coverage thereof and forward a signal received from the UE in the coverage thereof to the eNB. A radio link between the eNB and the RN is called a backhaul link, Un interface or X2 interface and a radio link between the RN and the UE is called an access link or Uu interface.
FIG. 1 illustrates an exemplary wireless communication system including a wired cell coordinator (WCC) connected to a plurality of eNBs. The WCC can be defined as a device deployed in an interference area of a plurality of eNBs to coordinate inter-cell interference. Inter-cell coordination can be regarded as control of collision between resources used by a plurality of cells. Furthermore, the WCC may include a remote radio head (RRH) function. An RRH corresponds to a wireless transceiver of an eNB, is deployed spaced apart from an eNB server and linked with the eNB server in a wired manner (e.g. using fiber optic cable, coaxial cable or the like). That is, the WCC may be regarded as an RRH connected to a plurality of eNBs. In addition, the WCC may further include a function of relaying a signal between an eNB and a UE. In the specification, the WCC is used as a device having the above-described configuration and functions.
Since the WCC is linked with a plurality of eNBs in a wired manner (which may be referred to as a backhaul link), the WCC can transmit and receive a large amount of signals more rapidly than a wireless backhaul link. Accordingly, radio channel overhearing is considerably decreased, compared to operation of an RN wirelessly connected to an eNB (overhearing refers to reception of a signal, transmitted form a transmitter to a destination node, by another node). Accordingly, the WCC can receive various downlink signals transmitted from eNBs to UEs through wired connection. In addition, the WCC may overhear a wireless uplink signal transmitted from a neighboring UE to an eNB.